/**
 * 题目要求
 * 
 * 使用帮助函数_average重构averageDollerValue,使用函数组合的方式实现
 * 
 */

const fp = require("lodash/fp")
const cars = [
    { name: 'Ferrari FF', horsepower: 660, dollar_value: 700000, in_stock: true },
    { name: 'Spyker C12 Zagato', horsepower: 650, dollar_value: 648000, in_stock: false },
    { name: 'Jaguar XKR-S', horsepower: 550, dollar_value: 132000, in_stock: false },
    { name: 'Audi R8', horsepower: 525, dollar_value: 114200, in_stock: false },
    { name: 'Aston Martin one-777', horsepower: 750, dollar_value: 1850000, in_stock: true },
    { name: 'Pagani Huayra', horsepower: 700, dollar_value: 1300000, in_stock: false },
]

let _average = function (xs) {
    return fp.reduce(fp.add, 0, xs) / xs.length
}

//重构下面的方法
/* let averageDollarValue = function (cars) {
    let dollar_values = fp.map(function (car) {
        return car.dollar_value
    }, cars)
    return _average(dollar_values)
} */

const fn = fp.flowRight(_average, fp.map(car => car.dollar_value))
console.log(fn(cars))